RM-
21Silver and Gold in New Mexico

Silver
and gold have been found in 163 mining districts and other geographic locations
in New Mexico. More than 3.2 million oz of gold and 117 million oz of silver
have been produced in New Mexico from 1848 through 2000. Production from
most districts has been small; however, 14 districts have produced more
than 3,000,000 oz of silver, and together they account for approximately
80% of the total silver production in New Mexico. Ten districts have produced
more than 150,000 oz of gold, and together they account for approximately
96% of the total gold production in New Mexico. Silver and gold are found
in 14 distinct types of deposits that range in age from Proterozoic through
Holocene. Five deposit types have produced significant gold and/or silver
as the primary product: placer, volcanic-epithermal, Great Plains margin
(alkaline-related), carbonate-hosted silver-manganese replacement, and Laramide
vein. Four deposit types have produced significant silver and gold as byproducts
of base-metal production: carbonate-hosted lead-zinc replacement, Laramide
skarn, porphyry copper, and Proterozoic massive-sulfide. The five remaining
deposit types with minor silver and/or gold production are: copper-silver
(±uranium) vein, Rio Grande rift, Mississippi Valley-type, sedimentary-copper,
and vein and replacement in Proterozoic rocks.

All 163 mining districts are described in the
text and located on the 24" x 29" map. The text also describes the classification
of silver and gold-bearing deposits into 14 distinct types. RM-21 supersedes
RM-15.